1. Field of the Invention
The present invention relates to laminated polymeric foam board articles comprising two or more polymeric foam boards laminated together to increase foam board thickness as well as a process for preparing such laminated foam board articles.
2. Description of Related Art
There is a desire in the field of polymeric foam boards to prepare boards having a thickness that exceeds 200 millimeters and to do so without using hydrochlorofluorocarbon blowing agents. Foam boards of such a thickness are desirable to prepare building structures with high levels of thermal insulation as well as other structures such as parking deck structures. Unfortunately, it is very difficult to extrude polymeric foam of good quality at a thickness that exceeds 200 millimeters using non-hydrochlorofluorocarbon blowing agents.
Freely stacking thinner boards is one way to achieve a greater thickness, but it is undesirable because the boards can slip during installation and even while in place if not installed securely. Slippage is a particular concern for parking deck applications where foam boards can experience frequent shear forces as traffic moves over them. Moreover, stacking multiple boards together at a construction site increases labor difficulties in handling and installing the multiple boards as well as creates opportunity for moisture to accumulate between boards and thereby increase thermal conductivity.
A single laminated board of desirable thickness is obtainable by gluing multiple boards together. Often, however, an application requires that a foam board have water vapor permeability, desirably homogeneous water vapor permeability, in order to avoid trapping moisture against a structure framework. Unless multiple boards are glued in such a manner that maintains water vapor permeability through the foam boards and the glued interface moisture build-up can be problematic. European Patent (EP) 1213118 discloses a solution to laminating boards together while maintaining water vapor permeability through the foam and glue interface. EP1213118 requires removing foam skin from entire surfaces of foam boards that adjoin one another and then adhering them together with a diffusion open adhesive.
It is desirable and would advance the art to provide laminate foam boards that have retained or increased water vapor permeability (decreased water vapor diffusion resistance) relative to laminated foam boards comprising skin on both adhered surfaces, but that did not require removing entire skins from foam surfaces. It would be further advantageous if the laminate of foam boards enjoyed particularly high shear strength so they would be well suited for flooring and parking deck applications.